Automatically-collapsible tap



Sept. 4, 1923.

Filed Feb. 25 1919 3 Sheets-Sheet l NM; m m VM RN N INVENTOR.

ATTORNEY.

Sept 4, 1923.

J. E. CAIN ET AL AUTOMATICALLY QOLLAPSIBLE TAP 5 Sheets-Sheet 2- Filed Feb; 25, 1919 ATTORNEY.

' Sept. 4, 1923.

J. E. CAIN ET AL AUTOMATICALLY COLLAPSIBLE TAP Filed'Feb. 25 1919 5 Sheets-Sheet 5 I INVEN TOR.

" MGM- A TTORNEY.

Patented Sept. 4, 1923 iii,

tsetse? rear oasis;

JACOB E. GAIN AND FRANK A. rALKnNBAcH, or coLUrrBos, orrro; WILLIAM znvr- MERER, ADMINISTRATOR or man nsra'rn or 'arn FEVANK-A. FALKENBAGH, AS- srenon on THE ENTIRE rnrnans'r or snrn ream; A; 'raLKnnBAoH TO ELLANOR FALKENBAGH.

AUTOMATIGALLY-GOLLAPSIBLE TAP. v

To (ZZZ 107mm it may concern:

Be it known that we Jncon E. CAIN and FRANK A. FALKENBACH, citizens of the United States of America, residing at C- lumbus, in the county 01 Franklin and State ot Ohio have invented certain new and useful Improvements in Automatically- Cob lapsihle Taps, of which the following is a specification.

Our present invention relates to automatically collapsible taps for cutting threads and consists in an improved structure resulting from a novel arrangement of parts which desirably brings about a more direct and effective cooperation of these parts in their assumption of the different positions of adjustment that necessarily occur in a device or" the type in question.

e have provided an automatically collapsible tap wherein the bits which are eX- -tended in operation and automatically withdrawn at the end of each operation are mounted upon a plunger structure that is ad justably mounted in a stock. An important iioature of our invention resides in the pro vision olia direct lOPklTlQj mechanism for automatically and positively locking the plunger in such position that the hits are extend ed, this locking mechanism being peculiarly novel both because of its direct action and because of its unique structural vfeatures. The preferred embodiment of'our invention is shown in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein-t Figure l is a side elevation of our collapsible tap.

Figure 2 is a section taken online 22 of Figure 1. looking in the direction of the arrows. r

Figure 3 is a section taken on line 3-3 of Figure 1. looking in the direction of the arrows.

Figure t is a longitudinal sectionvof our collapsible tap, showing the position of the parts when the bits are cxtendech Figure 5 is a longitudinal'section similar to the section shown in Figure 4: but showing the position of the parts when the bits are withdrawn by the collapsing action;

Figure 6 is a longitudinal section of a modified form of collapsible tap. v .7

Figure '7 is a section taken on line 7-7 of Figure 5, looking in the direction of the arrows.

In the drawings, the collapsible tap is shown as comprising a stock 1 with a reduced forward extension 2. Thisstockl is bored as at 3 and further has a bore at of a" relatively smaller diameter so as to produce a shoulder 5 at the juncture of the concentric bores 3 and 4.

Slidably mounted in the bore 4, is a plunger 6 provided at itsrear end with-an internally threaded socket? for the reception of a bolt 8 which extends rearwardly into the.

bore 3 and which in turn is threaded-at its rear extremity as at:9for the adjustable re-J ception of a-shouldered nut 10. Concentrically embracing the bolt 8 and the reduced section of the'nut 10 is a coil spring 11 which abuts the shoulder-oi? the nut 10 at one end and bears against a washer l2 abutting the sl'ioulder 5. It will be obvious from thisthat the spring: 11' normally tends to draw the plungcr fi rcarwardly and that the tension otthe spring ll may be varied by adjusting the nut ldupo'n the bolt 8. The rearward movement ot theplunger Rand the bolt 8 nieanso'i the plug 13 which is adjustably mounted in the threaded end of the bore 3. The hits Mare slidahly mounted upon the plunger 6 by means of the key slot structure shown, 15in Figure 3. These bits 14: extend through radial openings 16 in the may be 'ston iied at any desired point by by removal oft-he cap 17. They are capable though they are restrained from longitudinal movement with relation to the stock 1 by means of the walls of the openings 16.

It will be understood that the operation of our collapsible tap is the usual one to the extent that the bits are extended and set in extendedposition prior to-the time the bits start to operate upon the work. These bits remain extended during. the opcrationupon .end ot the stock 1 being; placed in position a of radial movement in such openings, al-

thework and until the work has. been tapped to the desired depth. At this inioo 1 stant, automatic mechanism is set in motion to automatically release the bits from their set position and withdraw them to a posi- {tion that will facilitate the ready 'removal I of such bits from the work being operated upon. The means for setting the bits in extended position takes the form of a lever fulcrumed at 18 in a radial slot 19 in the wall of the stock 1. This lever is provided with a rounded bearing end and may be designated 20. It is a lever of the first class. This is distinctly advantageous because the mechanical advantage is greater and also it is only necessary to provide one opening in the wall of the stock 1. The latter point is particularly important because experience has demonstrated that these collapsible taps get little or no cleaning in pra tice and ultiniately become clogged'with dirt and granu lar material of all kinds.

We have taken special steps to guard against this clogging action by the provision of a slidable block 21 with a platelike extension 22 that is slotted to fit snugly about the lever handle. This snug fitting is ensured by providing the lever handle at this point with a rounded portion The block 21 is longitudinally slidable in a slot in a collar 24 which surrounds the stock 1 and the plate-like extension slides'back and forth. in a space 25 between the collar 24 and an outer embracing collar 26.

When the plunger 6 is moved into position to extend the bits by means of the lever 20, as shown in Figure 4, this plunger 6 is automatically locked in such position by means of a spring pressed pin 27 disposed in a socket 28 in the plunger 6 and normally forced outwardly from the base of such socket by a coil spring 29. The 'iiianner in which this spring pressed pin automatically springs inte position to lock this plunger 6 in its forward position will be evident.

Cooperating with the spring pressed pin 27 for the purpose of automatically releasing the same is a floating pin 30 which bears at its inner end upon the spring pressed pin 27 and at its outer end is designed to rest in a recess 31 of a segmental member 32 slidably mounted within the collar 24. The floating pin 30 is carried by a segmental block member 33 which is mounted for lon gitudinal slidable adjustment upon the re duced portion of the stock 1 and which (-oi'itains a keeper socket 34 for the reception of the spring pressed pin when the plunger. 6 is in forward position. This slidable block member 33 is carriedin a slot in the stock 1 and is movable longitudinally with relation to the plunger 6 by means of an adjustable collar 35 to which it is keyed as at '36.

The floating pin 30 is inoicible'inwardly to force the spring pressed pin 27 inwardly to release the plunger 6 at the proper time by means of the collars 24 and 26. This operation is effected through the medium of a pin 37 on the outer surface of the block 32, this pin being positively shifted in a rotary direction by means of a cam slot 38 in the collar 24. It will be understood that the collars 2a and 26 are designed to be positively forced rearwardly by contact with the work at the desired instant. They are thus moved rearwardly against a. spring 39 which bears against a key 40. This key el-l) when moved with the collars 24- and 26 operates in a slot in the stock 1 so that these collars may not be rotated. The result is that the cam slot 38 in the collar 24 moves directly rearward and in doing this forces the pin 37 to one side with the result that the lock 32 is likewise moved to one side with the further result that the floating pin 30 rides out of its normal receiving slot in the block 32 and thus forces the spring presseed pin 27' inwardly to such a point that it will clear the walls of its keeper socket. When this occurs, the plunger 6 being unrestrained by the pin 27 is automatically moved rearwardly by the spring 11 and, in such rearward movement, withdraws the bits 14:. l

The outer collar 26 is adjustable with relation to the inner collar 24 and is loclred in any desired position by means of the set screws 41.. In operation. the outer collar 26 is initially adjusted so that it will contact with the work at an instant prior to the time when a sufficient depth of tapping will have occurred. The result is that at the in stant the'proper depth of tapping has occurred. the collar 26 is pressed rearwardly to such an extent that the spring pressed pin 27 is released in the manner described and the bits are automatically colla 'ised.

It will be understood that the adjustment of the degree to which the bits are to be extended is etl'ec'ted by a member 35 and that this member is calibrated as at 42 to fa hits or away from themyaccordins' to the direction in which it is turned. This longitudinal movement will be communicated to the segmental block member 33 through the out standing rib 36. Since the keeper socket 34 is in the segmental block member 33, any

movement of the segmental block member in a longitudinal direction will change the position at which the spring-pressed pin 27 engages the keeper socket 34. thus regulating the relative position of the plunger 6 with. the stock 1. By regulating the position of the plunger 6 with relation to the stock 1, the degree to which the bits l4 are extended may be accurately controlled. This member 35 is locked in any adjusted position by means of a keyed washer 43 and a lock nut 44.

A modification of our improved locking device is illustrated in Figure 6. The structural details of the collapsible tap shown in this figure are practically identical with the structure shown in the preceding figures with the following exception. Instead of a spring pressed pin 27, we have utilized a pawl A5 pressed outwardly by a spring 46 in a socket L7. This pawl is designed to automatically move into a keeper 48, whenever the plunger 6 is moved forward to proper position. In this position, the pawl -l5 is subject to a floating pin 4L9 which is operable in the manner explained in the description of the preceding figures to automatically release the pawl 4L5 and the plunger 6 at the proper instant.

Having thus described our invention, what we claim is:

1. A collapsible tap comprising a stock, a plunger, bits adjust-ably carried by said plunger, and means for automatically locking said plunger directly to said stock at variable positions of adjustment to vary the positions of the bits.

2. A collapsible tap comprising a stock, a plunger, bits mounted on said plunger and automatically extensible and collapsible by the movement of said plunger, a spring for moving said plunger in one direction, means for positively moving said plunger in the other direction, and a means for directly locking said stock and plunger in variable positions of adjustment to vary the positions of said bits.

3. A collapsible tap comprising a stock, a plunger, bits mounted on said plunger and automatically adjustable by the movement thereof, a spring for moving said plunger in one direction, means for moving said plunger in the other direction, and an automatic latch between the stock and plunger, the parts of said latch being adjustable to vary the relation of said stock and plunger when latching occurs.

i. A collapsible tap comprising a stock, a plunger, bits a-djustably carried by said plunger, a lever for adjusting said plunger extending through an opening in said stock and into an opening in said plunger, and a cover-plate for such opening slotted for the passage of such handle therethrough, said handle being rounded where it passes through said slot so as to produce a minimum clearance in all positions.

5. A collapsible tap comprising a stock, a plunger, bits adjustably carried by said plunger, and a locking device spring-pressed to lot-l: said plunger directly to said stock when it reaches a determinate position.

6. A collapsible tap comprising a. stock, a plunger, bits adjustably carried by said plunger, a locking device spring pressed to lock said plunger directly to said stock when it reaches a determinate position, and a means for auton'iatically releasing said look ing device.

7. A collapsible tap comprising a stock, a. plunger, bits carried by said plunger, a lever for adjusting said plunger extending through an opening in said stockand into an opening in said plunger, and a cover for such openings.

8. A collapsible tap comprising a stock, a plunger movable therein, bits carried by said plunger, a spring locking device between said plunger and said stock, a floating pin for releasing said locking device, a mechanism for automatically operating said floating pin to effect such release.

9. A collapsible tap' comprising a stock, a plunger, bits carried by'sai'd plunger, a spring pressed locking device, a release pin for said locking device and a partially rota table cam element movable at the proper instant in the tapping operation to force said releasing pin against said locking de vice to thereby release said locking device.

10. A collapsible tap comprising a stock, a plunger movable therein, bits carried by said plunger and adjustable radially by movement of said plunger to different positions in said stock, a latch and keeper tor holding said plunger in position with the bits extended, and means tor adjusting the keeper lengthwise of said stock to adjust the extent to which said bits are extended.

11. A collapsible tap comprising a stock, a plunger, bits adjust-ably carried by said plunger, and means for automatically locking said plunger directly to said stock at variable positions and for releasing said locking device.

In testimony whereof we hereby a [fix our signatures.

JACOB E. CAIN. I FRANK A. FALKENBACH. 

